Figure 3.

Hormonal regulation of PIN trafficking. PIN auxin exporters undergo constant, subcellular endocytic recycling, which assists in maintaining polar localization (Kleine-Vehn et al. 2011) and integrates various signals. PINs can as well be directed from the plasma membrane (PM) to the vacuole through the trans-Golgi network (TGN)/endosomal network for lytic degradation. Environmental and developmental signals, including hormones, can modulate various steps of PIN trafficking, thus changing PIN incidence at the PM. This eventually fine-tunes directionality and capacity of auxin transport leading to adaptation of plant growth and development. Figure based on data reviewed in Semeradova et al. (2020).